Alloy for valve seat insert castings



United States Patent 3,167,424 ALLOY FOR VALVE SEAT INSERT CASTINGS William C. Wick, Chicago, Ili., assignor to Wells Manufacturing Company, Skokie, 111., a corporation of Illinois No Drawing. Filed Dec. 21, 1961, Ser. No. 161,300 6 Claims. (Cl. 75-134) This invention relates, in general, to alloys, and has particular relation to alloys for valve seat insert castings.

One of the main objects of the present invention is the provision of an improved alloy which is particularly useful for valve seat insert castings, and which is useful for other applications having similar requirements. 7

Another object is to provide an alloy for valve seat insert castings which will have the characteristic of resisting thermal cracking at high temperatures in the range of 1500 F.

Another object is to provide an alloy of the character set forth, which alloy has good hot hardness properties, good corrosion resistance, is stable at elevated temperatures, has expansion compatible with the engine block into which the valve seat insert formed of the alloy is inserted, will retain a good seal, etc., between the valve and its seat so that leakage is avoided, and which can be used for heavy duty applications if necessary, such as for truck engines, diesel engines, etc.

Another object is to provide an alloy which will retain a high degree of hardness at elevated temperatures.

Another object is to provide an alloy which can be heat treated and stabilized against further size change on repeated heating and cooling.

Another object is to provide an alloy which will resist attack from internal combustion engine exhaust gases at high temperatures.

Another object is to provide an alloy which will retain its impact resistance at elevated temperatures.

Another object is to provide a new and improved combination of alloying elements comprising low cost elements for accomplishing the aforementioned ends at less total cost than present alloys.

Another object is to provide an alloy of the character set forth for valve seat insert castings in which the alloy and its production are less costly than materials of the Endurite, Eatonite and Stellite types.

Further features and advantages and adaptations of the invention will be apparent from the following detailed description, it being understood that the invention is limited only within the scope of the appended claims, and not to the particular embodiments selected for illustration.

The following specific ingredients, in substantially the proportions set forth, have proven to produce a highly satisfactory alloy for valve seat insert castings in which the objects and advantages set forth are achieved:

Percent Total carbon 2.50 Silicon 2.50 Manganese 1.00 ickel 40.00 Chromium 10.00 Molybdenum 7.00 Cobalt 7.00 Tungsten 7.00 Copper 1.50 Aluminum 1.50 Iron 20.00

In the above alloy formulation the amounts of cobalt and tungsten, which are expensive, are reduced by the 3,167,424 Patented J an. 26, 1965 ice nickel and iron. The aluminum, silicon and manganese also act as substitutes for cobalt.

Some prior alloys require pure chromium metal, the cost of which at present is about $1.00 per pound. The above formulation uses less chromium, and may use ferrochromium containing about 35% iron, the cost of which at present is about 35 cents per pound.

The chromium, molybdenum, cobalt and tungsten contribute to the hot hardness of the alloy.

The aluminum and copper contribute to corrosion resistance; also to heat treat properties, for producing a precipitation hardening phase.

The carbon is important from the hardness standpoint and produces chromium carbide, tungsten carbide, iron carbide, etc. i

The nickel and manganese for an austenite producing material contribute to the desired expansion characteristics of the alloy. 1

The manganese content also acts as a deoxidizerto help the castability of the alloy. Castability has reference to the fluidity of the alloy such that it can be properly poured and will produce the desired shape of casting without becoming sticky or tacky.

The silicon content is primarily for obtaining the desired Castability; also for corrosion resistance.

It is contemplated that an alloy according to the present invention for valve seat'insert castings may contain the ingredients or constituents in the following ranges:

, Percent Total carbon 2.25 to 2.75 Silicon 2.25 to 2.75 Manganese .75 to 1.25 Nickel Remainder Chromium 8.00 to 12.00 Molybdenum 6.00 to 8.00 Cobalt 6.00 to 8.00 Tungsten 6.00 to 8.00 Copper 1.00 to 2.00 Aluminum 1.00 to 2.00 Iron About 20.00

It is further contemplated that an alloy according to the present invention for valve seat insert castings, may contain the ingredients or constituents in the following somewhat wider ranges:

Percent Total carbon .85 to 3.50 Silicon 1.50 to 3.50 Manganese .50 to 3.00 Nickel Remainder Chromium 5.00 to 20.00 Molybdenum 4.00 to 12.00 Cobalt 4.00 to 12.00 Tungsten 4.00 to 12.00 Copper .20 to 6.00 Aluminum .20 to 4.00 Iron 5.00 to 35.00

Alloys made in accordance wtih the present invention provide the desired properties hereinbefore set forth and are resistant to constituents which may be present or result from the combustion of the fuels used for the engines with which the valve seat inserts are employed.

The embodiments of the invention disclosed in the specification are for illustrative purposes only, and it is to be expressly understood that the specification is not to be construed as a definition of the limits or scope of the invention, reference being had to the appended claims for that purpose.

a a I claim: 1. 'An alloy consisting essentially of:

Percent Iotal carbon 2.50 Silicon 2.50 Manganese 1.00 Nickel 40.00 Chromium 10.00 Molybdenum 7.00 Cobalt 7.00 Tungsten 7.00 Copper 1.50 Aluminum 1.50

Iron 20.00

2. alloy consisting essentially of:

. Percent Total carbon 2.25 to 2.75 Silicon 2.25 to 2.75 Manganese .75 to 1.25 Nickel Remainder Chromium 8.00 to 12.00 Molybdenum 6.00 to 8.00 Cobalt 6.00 to 8.00 Tungsten 6.00 to 8.00 Copper 1.00 to 2.00 Aluminum- 1.00 to 2.00 Iron About 20.00

' 3. An alloy consisting essentially of: Percent Total carbon .85 to 3.50 Silicon 1.50 to 3.50 Manganese p .50 to 3.00 Nickel Remainder 'Chromium 5.00 to 20.00 Molybdenum 4.00 to 12.00 Cobalt 4.00 to 12.00 Tungsten 4.00 to 12.00 Copper .20 to 6.00 Aluminum .20 to 4.00

Iron 5.00 to 35.00

4. A valve seat insert casting comprising an alloy consisting essentially of about 2.50% carbon, about 2.50%

silicon, about 1.00% manganese, about 40.00% nickel,

sisting essentially of from about 2.25% to about 2.75% total carbon, from about 2.25 to about 2.75% silicon,

from about .75% to about 1.25% manganese, from about 8.00% to about 12.00% chromium, from about 6.00% to about 8.00% molybdenum, from about 6.00% to about 8.00% cobalt, from about 6.00% to about 8.00% tungsten, from about 1.00% to about 2.00% copper, from about 1.00% to about 2.00% aluminum, about 20.00% iron, and the remainder nickel. p

6. A valve seat insert casting comprising an alloy consisting essentially of from about .85% to about 3.50% total carbon, from about 1.50% to about 3.50% silicon, from about to about 3.00% manganese, from about 5.00% to about 20.00% chromium, from about 4.00% to about 12.00% molybdenum, from about 4.00% to about 12.00% cobalt, from about 4.00% to about 12.00% tungsten, from about 20% to about 6.00% copper, from about .20 to about 4.00% aluminum, from about 5.00% to about 35.00% iron, and substantially the remainder nickel.

References Cited by the Examiner UNITED STATES PATENTS 2,742,356 4/56 P rasse et a1. 171 2,827,373 3/58 Prasse. et a1. 75134.3 2,996,378 8/61 Edmonds et al. 75171 3,099,128 7/63 Straumann 75l71 X FOREIGN PATENTS 591,641 1/ 34 Germany.

DAVID L. RECK, Primary Examiner.

RAY K. WINDHAM, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,167 ,424 January 26 1965 William C. Wick It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 6, for "2.00%" read 20.00% line 25 for ".20" read .Z0%

Signed and sealed this 29th day of June 1965.

(SEAL) Altest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

6. A VALVE SEAT INSERT CASTING COMPRISING AN ALLOY CONSISTING ESSENTIALLY OF FROM ABOUT .85% TO ABUT 3.50% TOTAL CARBON, FROM ABOUT 1.50% TO ABOUT 3.50% SILICON, FROM ABOUT .50% TO ABOUT 3.00% MANGANESE, FROM ABOUT 5.00% TO ABOUT 20.00% CHROMIUM, FROM ABOUT 4.00% TO ABOUT 12.00% MOLYBEDENUM, FROM ABOUT 4.00% TO ABOUT 12.00% COBALT, FROM ABOUT 4.00% TO ABOUT 12.00% TUNGSTEN, FROM ABOUT .20% TO ABOUT 6.00% COPPER, FROM ABOUT .20 TO ABOUT 4.00% ALUMINUM, FROM ABOUT 5.00% TO ABOUT 35.00% IRON, AND SUBSTANTIALLY THE REMAINDER NICKEL. 